The disclosure relates to a mixer for mixing at least two flowable components and to a dispensing apparatus in accordance with the preamble of the respective independent claim.
Static or dynamic mixers for mixing at least two components are used in a plurality of technical fields; for example in the mixing of two-component systems such as sealing compounds, two-component foams or two component adhesives or also in the dental field, for example for mixing impression materials. The individual components usually have to remain separate from one another until use and are then mixed so that hardening subsequently takes place by a chemical reaction. Such mixers are as a rule designed for single use because they can practically no longer be cleaned after hardening or after any other reaction of the components.
Such mixers are usually part of a dispensing apparatus which include cartridges or other chambers for the respective components. In use, the individual components are dispensed from the chamber by means of a plunger or by means of a drivable piston, move into the mixer, are intimately mixed there and exit the mixer through its outlet opening as a homogeneously mixed mass. There are many different designs with respect to the chambers for the components. The chambers can be designed, for example, as rigid cartridges which are inserted directly into the dispensing apparatus. In this respect, the cartridges can, for example, each have a piston as a base which is moved in the cartridge by exertion of pressure to dispense the respective component. Designs are also known in which the cartridges have very thin walls. They are then inserted into support cartridges of the dispensing apparatus and there have pressure exerted on them by a plunger or by a piston. Provision can be made in this respect that the thin-walled cartridge collapses on dispensing in the support cartridge. It is furthermore known that the chambers for the components are each designed as tubular bags which are then inserted into support cartridges and are compressed by pressure exertion for use.
As a rule, it is necessary for the storage of the individual components that they are stored in completely closed chambers to avoid any unwanted reaction with air or its components, drying or any other degradation. It is often in particular wanted to dispense with complex closure devices for the chambers with tubular bags or thin-walled cartridges as chambers for the components. It is therefore a widespread measure that the respective chamber, that is the cartridge or the tubular bag, for example, is pierced before the first use so that subsequently the corresponding component can be dispensed.
Systems are known in which an adapter is placed onto the cartridge or a holder for the tubular bag which includes a piercing device, wherein two positions are provided for the adapter, one in which the piercing device is held tight by the cartridge or by the bag respectively for storage and for transport and a second in which the piercing device penetrates into the cartridge, pierces it and thus releases the component for dispensing.
It is disadvantageous with this that the adapter is part of the disposable system and therefore has to be disposed of. As a rule, special locking devices are also required to avoid any unintentional piercing.
Other embodiments have the piercing device attached directly to the holder for the cartridge or the tubular bag respectively. If the cartridge or the tubular bag respectively is inserted and is exposed to pressure, the piercing of the wall takes place in that the latter is pressed toward the piercing device and is thereby cut open. This system is not always reliable and as a rule requires great care in storage, in transport and in handling so that the cartridge or tubular bag respectively is not unintentionally pierced.
Such systems are also known, for example from DE-196 18 693, in which the piercing devices are provided at the inlet passages of the mixer, for which purpose they are designed as obliquely cut-out pipe ends which each engage into an outlet of a chamber when the mixer is placed on and in so doing pierce the wall of the chamber. It may, however, occur in this embodiment that the pierced wall lays itself in front of the entry opening of the inlet passages and covers them at least partly, whereby the dispensing of the component is negatively influenced. This could optionally be prevented by a large penetration depth of the inlet passage into the cartridge or into the tubular bag, but the complete dispensing of the components from the cartridges or from the tubular bags respectively thereby becomes impossible, which results in uneconomic residual quantities. It is the object of the invention to comply as much as possible with this endeavor and to avoid the named disadvantages of the prior art.
Starting from this prior art, it is therefore an object of the invention to propose a mixer and a dispensing apparatus for at least two flowable components which do not have these disadvantages. A problem-free, secure storage and transport should be possible, the handling of the system should be easy and an impeding of the dispensing of the component through the pierced wall should be avoided as much as possible.
The subject matters of the disclosure satisfying these objects are characterized by the features of the respective independent claims.